迁移至JBoss 7.4后Richfaces的render属性失效求助

环境 #

• Java 8
• RichFaces 4.5.0.Final（已升级至4.5.17.Final）
• OmniFaces 2.7（已升级至3.0）

问题 #

应用迁移到JBoss 7.4后，所有使用RichFaces render 属性的页面均无法正常渲染，抛出NullPointerException。

异常堆栈 #

09:28:53,389 SEVERE [javax.enterprise.resource.webcontainer.jsf.application] (default task-6) Error Rendering View[/views/operations/ci/list.xhtml]: java.lang.NullPointerException
    at org.richfaces.resource.ResourceHandlerImpl.getRendererTypeForResourceName(ResourceHandlerImpl.java:299)
    at javax.faces.application.ResourceHandlerWrapper.getRendererTypeForResourceName(ResourceHandlerWrapper.java:217)
    at javax.faces.application.ResourceHandlerWrapper.getRendererTypeForResourceName(ResourceHandlerWrapper.java:217)
    at com.sun.faces.context.PartialViewContextImpl.renderComponentResources(PartialViewContextImpl.java:482)
    at com.sun.faces.context.PartialViewContextImpl.processPartial(PartialViewContextImpl.java:314)
    at org.richfaces.context.ExtendedPartialViewContext.processPartial(ExtendedPartialViewContext.java:264)
    at javax.faces.context.PartialViewContextWrapper.processPartial(PartialViewContextWrapper.java:228)
    at org.omnifaces.context.OmniPartialViewContext.processPartial(OmniPartialViewContext.java:122)
    at javax.faces.component.UIViewRoot.encodeChildren(UIViewRoot.java:1102)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1647)
    at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:442)
    at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:170)
    at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:132)
    at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:132)
    at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:132)
    at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:132)
    at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:132)
    at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:132)
    at org.omnifaces.viewhandler.OmniViewHandler.renderView(OmniViewHandler.java:115)
    at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:132)
    at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:102)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:76)
    at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:199)
    at org.apache.myfaces.extensions.cdi.jsf2.impl.listener.phase.CodiLifecycleWrapper.render(CodiLifecycleWrapper.java:126)
    at javax.faces.webapp.FacesServlet.executeLifecyle(FacesServlet.java:708)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:451)
    at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:74)
    at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:129)

解决方法 #

1. 对齐JSF版本兼容性 #

JBoss 7.4内置Mojarra 2.3.x，但RichFaces 4.5.x仅兼容Mojarra 2.2。即使升级RichFaces到4.5.17，仍可能存在版本冲突。建议：

• 在jboss-deployment-structure.xml中排除JBoss内置JSF模块，将兼容的Mojarra 2.2打包进应用：

<jboss-deployment-structure>
    <deployment>
        <exclude-subsystems>
            <subsystem name="jsf" />
        </exclude-subsystems>
        <exclusions>
            <module name="javax.faces.api" />
            <module name="com.sun.jsf-impl" />
        </exclusions>
    </deployment>
</jboss-deployment-structure>

2. 修复ResourceHandler空指针 #

异常出现在ResourceHandlerImpl.getRendererTypeForResourceName，通常是资源名称为空导致。可以自定义包装类做防护：

public class SafeResourceHandler extends ResourceHandlerWrapper {
    private final ResourceHandler delegate;

    public SafeResourceHandler(ResourceHandler delegate) {
        this.delegate = delegate;
    }

    @Override
    public String getRendererTypeForResourceName(String resourceName) {
        return resourceName == null ? null : delegate.getRendererTypeForResourceName(resourceName);
    }

    @Override
    public ResourceHandler getWrapped() {
        return delegate;
    }
}

在faces-config.xml注册该处理器：

<application>
    <resource-handler>com.your.project.SafeResourceHandler</resource-handler>
</application>

3. 调整OmniFaces版本 #

OmniFaces 3.0要求JSF 2.3，与RichFaces 4.5.x不兼容。建议降级OmniFaces到2.14（JSF 2.2兼容的最新稳定版），搭配RichFaces 4.5.17使用。

4. 检查页面render属性 #

确认页面中render属性引用的组件ID存在且拼写正确，避免EL表达式返回空值或指向不存在的组件。

内容的提问来源于stack exchange，提问作者Roubben